一個英文文法問題 -- 應該用in 定at？

It should be "in".

"At" is used to describe the location of something HAPPENS. For
instance, the people arrived late at the airport. The action involved is
"arrived late".

"In" is used to descibe something within an area AT A POINT. For
example: a country in Africa. There are no actions involved.

Therefore, in your case, "in" should be used because there are no
action involved in the people. They are staying in USA which is
something AT A POINT.

2009-05-05 18:28:41 補充：
correct spelling of "knowledge" in 參考資料.

in a place 在某處

do you live in london now?
但如果地點用可數名詞人(如 union,republic,states,kingdom)
便需加上 the
In the USA 是 在美國 ,Speaking of that stay in American of...係說到在美國的人......意思.

您好，我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源，您能從中得到不少幫助：

http://www.hkenglishstudy.info

祝您好運!

你好，我的答案跟 002 是一样的，正确的是 The people in the USA，因为我们通常加个 the 在 Republic，Kingdom，States 等等的国家。

USA 就是 United States of America。

希望能帮到你咯。。。: )

2009-05-12 13:03:27 補充：
你好，我真是想你知道的是，我们不只要选 in 还要加个 the 在 USA 的前面。

希望能帮到你咯。。。: )

Yours are correct, should be in.

I think the answer is ''in''

in

你同事的不.

正確是: in the USA

當然係 “in" 啦 ﹗ 你個同事錯左。